JP5221223B2 - Chargeable filter member with excellent dust separation - Google Patents

Description

  The present invention collects dust and dust made of particulate floating substances charged by friction and corona discharge treatment, and has excellent dust separation property made of fibers from which the collected dust and dust can be easily removed. The present invention relates to a property filter member.

  In recent years, various allergic diseases caused by floating substances such as cedar pollen, mite carcasses, mold spores, and house dust have become serious social problems. Since these particulate floating substances are a new cause of indoor environmental pollution, submicron order particulate floating substances should be used in vacuum cleaners and air cleaners to clean indoor environments. A HEPA filter using electretized fibers is used for efficient collection. It is generally known that these filters are clogged due to collected particulate floating substances when used for a long period of time due to their collection principle and structure, leading to a decrease in collection efficiency and an increase in pressure loss. It has been.

In general, in order to efficiently collect particulate floating substances of submicron order, filters using electret fibers having excellent collection efficiency are used (for example, Patent Document 1 and Patent Document). 2). The electretization method includes a method in which electrons are injected into the fiber by corona discharge to cause orientation of the dipole, and a method in which two or more different fibers are rubbed and frictional charging generated at that time is used. When electretized by these methods, although it depends on the type of fiber material, it can be permanently charged, and it is possible to efficiently collect particulate floating substances for a long period of time.
JP-A-1-287914 JP 2001-214327 A

  However, the principle of collection by electretized fibers is to collect particulate floating substances by the electrostatic attraction of the charged fiber surface, and the collected particulate floating substances are permanently charged. It adheres to the surface of the fiber made of polyolefin resin such as polypropylene, polyethylene, polyethylene terephthalate, polytetrafluoroethylene by electrostatic attraction. Therefore, it is difficult to easily remove the particulate floating substances adhering to the fiber surface, and the particulate floating substances collected on the filter surface with the passage of time of use accumulate and cause clogging. This is a major cause of a decrease in collection efficiency and an increase in pressure loss.

  Therefore, it is possible to provide a filter capable of suppressing a decrease in collection efficiency and an increase in pressure loss if the accumulated particulate suspended matter can be easily removed from the filter surface even when charged. Is excellent in performance (hereinafter referred to as “dust separation”) that the surface of the fiber is charged and particulate suspended matter collected by static electricity when the filter is cleaned can be easily removed from the fiber surface of the filter. There are no proposals for filter members.

  The present invention has been made to solve such a conventional problem. By fixing inorganic fine particles of a dielectric coated with a silane monomer on the surface of a resin fiber, the present invention can be easily performed by corona discharge or friction. The present invention is completed by finding that the particulate floating substances that are charged and efficiently collect the particulate floating substances and that can be easily removed from the fiber surface of the filter can be collected. It came to.

That is, the first invention, Ri Do a resin fiber, and electret possible substrates, provided in a surface portion of the base include inorganic fine particles of unsaturation or a reactive functional group is coated with a silane monomer having a dielectric The inorganic fine particles in the thin film form a thin film by chemically bonding unsaturated bonds or reactive functional groups of the silane monomers with each other. The substrate and the thin film are fixed by chemically bonding the saturated bond or reactive functional group to the surface portion of the substrate, and the thin film is formed by a single or a plurality of inorganic fine particles scattered in islands. by having a gap portion, Yusuke via the void portion is exposed a part of the surface of the substrate, the monomers, oligomers, at least one dielectric selected from the group consisting of polymers It is to provide excellent chargeability filter member dust releasability, which comprises a compound.

Furthermore, the present invention is the first invention, the thin film on the surface, for chargeable filter having excellent dust releasability, wherein a coating comprising a compound having a dielectric is formed A member is provided.

Furthermore, the present invention provides a member for a chargeable filter excellent in dust separation property, characterized in that, in the first or second invention, the chemical bond is graft polymerization.

Furthermore, the present invention provides a member for a chargeable filter excellent in dust separation characteristics, characterized in that, in the third invention, the graft polymerization is radiation graft polymerization.

According to the present invention, a thin film made of dielectric inorganic fine particles is chemically treated with a silane monomer having an unsaturated bond or a reactive functional group coated on the surface of the inorganic fine particles on at least the surface of the substrate fiber made of resin. binding is immobilized, and, since the inorganic fine particles are also formed by combining a silane-monomer, an electron injection or by corona discharge, it is possible to charge the like due to friction fibers or films, from this, Particulate suspended substances can be collected by electrostatic attraction.

  In addition, the surface of the thin film made of dielectric inorganic fine particles has nano-order minute irregularities, so the area of particulate suspended matter that has been collected and adhered is extremely small, and excellent dust separation is achieved. Therefore, it is possible to provide a filter member that is suitable for a vacuum cleaner, an air conditioner, an air cleaner, a building air conditioner, a clean room air conditioner, and the like and that has a low pressure loss and a high collection efficiency.

(First embodiment)
Below, the member for chargeable filters excellent in the dust separation property of embodiment of this invention is explained in full detail.

  FIG. 1 is an enlarged view of a part of a cross-section of a chargeable filter member 100 having excellent dust separation properties according to an embodiment of the present invention. In this embodiment, the chargeable filter member 100 having excellent dust separation property is a silane having an unsaturated bond or a reactive functional group in which a dielectric inorganic fine particle 2 is coated on a substrate 1 on the surface of the inorganic fine particle 2. The inorganic fine particles are bonded to each other through the monomer 3 and are fixed to the surface of the substrate 1.

  In FIG. 1, in order to show the embodiment of the present invention in an easy-to-understand manner, the thin film 10 containing dielectric inorganic fine particles is shown as a single type of fine particles. You may form with 2 or more types of microparticles | fine-particles.

  A silane monomer 3 having an unsaturated bond or a reactive functional group is oriented on the outermost surface of the dielectric inorganic fine particle 2 of this embodiment so that the unsaturated bond or the reactive functional group faces the outside of the inorganic fine particle 2. To form a coating. Since the silanol group at one end of the silane monomer 3 is hydrophilic, it is attracted to the surface of the inorganic fine particles 2 that are hydrophilic. On the other hand, the unsaturated bond and the reactive functional group at the reverse end are hydrophobic, so they tend to leave the surface of the inorganic fine particles 2. For this reason, the silanol group of the silane monomer 3 is bonded to the surface of the inorganic fine particle 2 by dehydration condensation, and the silane monomer 3 is oriented with the unsaturated bond or the reactive functional group facing outward.

  As a specific treatment method, the silane monomer 3 is added to a solution in which the inorganic fine particles 2 are dispersed in an organic solvent, and are pulverized to be fine particles. Then, the dispersion solution is solid-liquid separated, and the resulting inorganic fine particles are obtained. There is a method in which 2 is heated at 100 ° C. to 180 ° C. to bond the silane monomer 3 to the surface of the inorganic fine particles 2. Moreover, after adding the silane monomer 3 to the solution which disperse | distributed the inorganic fine particle 2 in the organic solvent, and making it microparticles | fine-particles by grinding | pulverization, the said dispersion solution is moved to the flask provided with the cooling tube, and a flask is heated with an oil bath. There is a method in which the silane monomer 3 is bonded to the surface of the inorganic fine particles 2 by treatment.

  The introduction amount of the silane monomer 3 on the surface of the inorganic fine particles 2 by the condensation reaction may be such that 0.5 to 100% of the surface of the inorganic fine particles 2 is covered with the silane monomer 3.

  In addition, the diameter of the inorganic fine particles and the fine particle diameters of the other various materials are not particularly limited as long as they are prepared by the method of the present embodiment. Is preferably 300 nm or less. Furthermore, if the average particle diameter is 100 nm or less, stronger bonding to the substrate 1 is achieved, which is more preferable from the viewpoint of durability.

  As a material constituting the substrate 1 used for the filter member 100 of the present embodiment, any material can be used as long as the chemical bond 4 by the silane monomer 3 having an unsaturated bond or a reactive functional group is possible. Examples of such materials include various resins, synthetic fibers, and natural fibers.

  In the present embodiment, as the form of the resin constituting the substrate 1, a fiber structure including a woven fabric, a knitted fabric, a non-woven fabric and the like made of a fibrous material can be applied. Examples of synthetic fibers constituting the substrate 1 include polyester fibers, polyamide fibers, polyvinyl alcohol fibers, acrylic fibers, vinyl chloride fibers, vinylidene chloride fibers, polyolefin fibers, polycarbonate fibers, fluorine fibers, And polyurea fiber, elastomer fiber, Beckley (registered trademark), and composite fiber of the material constituting these fibers and the resin material.

As the inorganic fine particles 2 of the dielectric material used in the chargeable filter member 100 excellent in dust separation of the present embodiment, nonmetal oxide, metal oxide, metal composite oxide, or the like is used. Further, the crystallinity of the inorganic fine particles 2 may be either amorphous or crystalline. Examples of the non-metal oxide include silicon oxide. In addition, as metal oxides, magnesium oxide, barium oxide, barium peroxide, aluminum oxide, tin oxide, titanium oxide, zinc oxide, titanium peroxide, zirconium oxide, iron oxide, Examples thereof include iron hydroxide, tungsten oxide, bismuth oxide, and indium oxide. Examples of the metal composite oxide include barium oxide, cobalt aluminum oxide, lead zirconium oxide, lead niobium oxide, TiO ₂ —WO ₃ , Al ₂ O ₃ —SiO ₂ , and WO ₃ —ZrO _{2. and,} like WO 3 -SnO _2.

  On the surface of the inorganic fine particles 2, catalyst fine particles made of noble metals such as Au, Pt, Pd, Rh, Ru, and catalyst fine particles made of oxides such as Ni, Co, Mo, W, Mn, Cu, V, Se, etc. Fine particles may be attached.

  The member for a chargeable filter excellent in dust separation of the present embodiment is obtained by applying a thin film 10 made of dielectric inorganic fine particles 2 on the above-described substrate 1 with a silane monomer 3 having an unsaturated bond or a reactive functional group. It is fixed by chemical bonds 4 (black circles in the figure).

  Specific examples of the unsaturated bond and reactive functional group of the silane monomer 3 include a vinyl group, an epoxy group, a styryl group, a methacrylo group, an acryloxy group, an isocyanate group, and a thiol group.

  The chargeable filter member of the present embodiment having excellent dust removability is obtained by using the silane monomer 3 having excellent reactivity, so that the inorganic fine particle 2 is converted into the inorganic fine particle 2 by the dehydration condensation reaction of the silanol group of the silane monomer 3. The filter member is bonded to the surface of the substrate 1 by the chemical bond 5 and the chemical bond 5 of the functional group to the fiber surface of the substrate 1 by graft polymerization described later.

As an example of the silane monomer 3 used in the charging filter member 100 excellent in dust separation of the present embodiment, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, N-β- ( N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane, N- (vinylbenzyl) -2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride, and 2- (3,4 epoxy cyclohexyl) Ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3- Methacryloxypropylmethyldimethoxysilane and 3-methacryloxy And trimethoxysilane, 3-meth and methacryloxy propyl methyl diethoxy silane, and 3-methacryloxypropyl triethoxysilane, 3-acrylic or trimethoxy silane, and 3-isocyanate propyl triethoxy silane.

  The silane monomer 3 is used alone or in combination of two or more. The silane monomer 3 is used by dissolving a necessary amount of the silane monomer 3 in an organic solvent such as methanol, ethanol, acetone, toluene or xylene. In addition, in order to improve dispersibility, mineral acids such as hydrochloric acid and nitric acid are added.

  Solvents used include lower alcohols such as ethanol, methanol, propanol and butanol, lower alkyl carboxylic acids such as formic acid and propionic acid, aromatic compounds such as toluene and xylene, and esters such as ethyl acetate and butyl acetate. And cellosolves such as methyl cellosolve and ethyl cellosolve may be used alone or in combination.

  The inorganic fine particles 2 used in the chargeable filter member 100 having excellent dust separation properties according to the present embodiment are used for production in a state dispersed in the solution of the silane monomer 3 described above. The inorganic fine particles 2 are dispersed by agitation and dispersion using a homomixer or a magnetic stirrer, pulverization / dispersion using a ball mill, sand mill, high-speed rotary mill or jet mill, or dispersion using ultrasonic waves.

  The inorganic fine particles 2 are used in the manufacture of the chargeable filter member 100 having excellent dust separation properties in the state of a dispersed colloidal dispersion or a dispersion obtained by pulverization. The dispersion of inorganic fine particles 2 is obtained by adding silane monomer 3 to a colloidal dispersion or a dispersion obtained by pulverization, and then dehydrating and condensing silane monomer 3 on the surface of inorganic fine particles 2 while heating under reflux. After forming the coating composed of the silane monomer 3 by bonding by reaction, after adding the silane monomer 3 to the dispersion obtained by micronization by pulverization, or after micronization by pulverization by adding the silane monomer 3 The silane monomer is bonded to the surface of the inorganic fine particles 2 by a dehydration condensation reaction after solid-liquid separation and heating at 100 to 180 ° C., and then pulverized and pulverized for redispersion.

  After adding the silane monomer 3 to the dispersion obtained by micronizing by pulverization or by adding silane monomer 3 and micronizing by pulverization, solid-liquid separation and heating at 100 to 180 ° C to silane monomer In the case where 3 is reactively bonded to the surface of the inorganic fine particles 2, the substrate 1 in which at least the surface of the inorganic fine particles 2 is made of resin is provided if the coverage of the silane monomer on the surface of the inorganic fine particles 2 is 0.5% to 100%. There is no practical problem with the bonding strength to the surface.

  Next, a method of chemically bonding the substrate 1 to the dielectric inorganic fine particles 2 having a silane monomer bonded to the surface and the substrate 1 will be described. In the present embodiment, as a method for chemically bonding, a bonding method by graft polymerization is preferably used.

  Examples of the graft polymerization in the filter member 100 of the present embodiment include graft polymerization using a peroxide catalyst, graft polymerization using heat and light energy, and graft polymerization using radiation (radiation graft polymerization).

  Of these, radiation graft polymerization is particularly suitable from the viewpoints of simplicity of the polymerization process and production speed. Here, examples of the radiation used in the graft polymerization include α rays, β rays, γ rays, electron beams, ultraviolet rays, and the like. Lines and ultraviolet rays are particularly suitable.

  The filter member 100 using the graft polymerization in the present embodiment is suitably manufactured by the method described below.

  The first preferred method in the present embodiment is as follows. First, the solution in which the inorganic fine particles 2 chemically bonded with the silane monomer 3 are dispersed is applied to the surface (resin surface) of the substrate 1 to be bonded, and the solvent is removed by a method such as heat drying if necessary. After that, the silane monomer 3 is grafted onto the surface of the substrate 1 by irradiating the surface of the substrate 1 coated with the inorganic fine particles 2 chemically bonded to the silane monomer 3 with radiation such as γ rays, electron beams or ultraviolet rays. A so-called simultaneous irradiation graft polymerization in which the inorganic fine particles 2 are bonded simultaneously with the polymerization is performed.

  The second preferred method in the present embodiment is as follows. First, the surface of the substrate 1 is irradiated with radiation such as γ rays, electron beams, or ultraviolet rays in advance. Thereafter, the binder component 4 is added to a solution in which the inorganic fine particles 2 chemically bonded to the silane monomer 3 are dispersed, and a sufficiently mixed solution is applied to the surface of the substrate 1, whereby the silane monomer 3 and the substrate 1 are bonded. A so-called pre-irradiation graft polymerization in which the inorganic fine particles 2 are bonded simultaneously with the reaction is performed.

  In the present embodiment, as described above, the solution in which the inorganic fine particles 2 to be immobilized are dispersed is applied to the surface of the substrate 1 to be immobilized to produce a filter member.

  As a specific method for applying the dispersion liquid of the inorganic fine particles 2, generally used spin coating method, dip coating method, spray coating method, cast coating method, bar coating method, micro gravure coating method, A gravure coating method may be used. In addition, various methods such as screen printing, pad printing, offset printing, dry offset printing, flexographic printing, and inkjet printing are used as a method for partial application. It will not specifically limit if the suitable application | coating can be performed.

  Further, in order to perform graft polymerization of the silane monomer 3 efficiently and uniformly, the surface of the substrate 1 is previously subjected to corona discharge treatment, plasma discharge treatment, flame treatment, chromic acid, perchloric acid, or the like. Hydrophilic treatment may be performed by chemical treatment with an alkaline aqueous solution containing an oxidizing acid aqueous solution or sodium hydroxide.

  As described above, according to the charging filter member 100 excellent in dust separation of the present embodiment, the thin film 10 containing the inorganic fine particles of the dielectric is at least on the fiber surface of the substrate 1 whose surface is made of resin. By the corona discharge, the inorganic fine particles are fixed by chemical bonding by the silane monomer 3 having an unsaturated bond or reactive functional group covering the surface of the inorganic fine particles, and the inorganic fine particles are also bonded by the silane monomer. Since charging can be performed by electron injection or friction caused by a fiber or a film, the particulate floating substance can be collected by electrostatic attraction.

  Furthermore, since the surface of the thin film 10 containing inorganic fine particles of dielectric is formed with minute irregularities on the order of nanometers, the adhesion area of the particulate floating substances collected and adhered is extremely small, and excellent dust Expresses separability. Accordingly, the particulate floating substance adhering to the surface of the thin film 10 containing the inorganic fine particles of the dielectric can be easily detached by vibration, impact, or suction by a vacuum cleaner, and is thus collected with a low pressure loss. The filter can be applied to an air cleaner, an air conditioner, a vacuum cleaner, etc. as a filter that is excellent in efficiency and can prevent the collection of collected particulate floating substances.

  Further, the unsaturated bond or reactive silane monomer 3 having a reactive unsaturated group or reactive functional group is chemically bonded to the surface of the substrate 1 by the dehydration condensation reaction. The inorganic fine particles 2 are immobilized by reacting with the unsaturated bonds or reactive functional groups introduced on the surface of the inorganic fine particles 2 or with the resin surface of the substrate 1. Thereby, in the filter member 100 of the present embodiment, the inorganic fine particles 2 coated with the silane monomer 3 and the inorganic fine particles 2 and the substrate 1 are strongly bonded and have excellent durability. Property and dust separation effect can be maintained for a long time.

(Second Embodiment)
Next, the chargeable filter member 200 having excellent dust separation properties according to the second embodiment of the present invention will be described in detail with reference to FIG.

  FIG. 2 is an enlarged view of a part of the cross section of the chargeable filter member 200 having excellent dust separation properties according to the second embodiment of the present invention. The chargeable filter member 200 excellent in dust separation of the present embodiment is formed in and on the thin film 20 containing dielectric inorganic fine particles 2 formed of dielectric inorganic fine particles 2 coated with the silane monomer 3. The filter member 100 according to the first embodiment of the present invention is different from the filter member 100 according to the first embodiment of the present invention in that a compound having a dielectric property including at least one of a monomer, an oligomer, and a polymer is dispersed.

  Hereinafter, the manufacturing method and the configuration of the members, which are different from the filter member 100 according to the first embodiment of the present invention, will be described. Further, with respect to the base material and the fine particle material and the manufacturing method, the description of the points in common with the filter member of the first embodiment of the present invention will be omitted.

  In the chargeable filter member 200 excellent in dust separation performance of the present embodiment, the dielectric compound 5 containing at least one of a monomer, an oligomer, and a polymer is contained in the thin film 20 made of the dielectric inorganic fine particles 2. It is a big feature to include.

  Specific examples of the compound 5 having dielectric properties include monofunctional, bifunctional, and polyfunctional vinyl monomers having an unsaturated bond or a reactive functional group, such as acrylic acid, methylmethyl methacrylate, ethyl acrylate, and n-butyl. Acrylate, 2-hydroxyethyl acrylate, methyl methacrylate, 2-hydroxyethyl acrylate, acrylamide, methacrylamide, acrylonitrile, vinyl acetate, styrene, itaconic acid, trimethylolpropane triacrylate, pentaerythritol triacrylate, and the like are used.

  Furthermore, as the compound 5 having dielectric properties, for example, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, N-β-, which is a silane monomer having an unsaturated bond or a reactive functional group. (N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane or the like is used.

Further, as the compound 5 having dielectric properties, an alkoxylane compound represented by Si (OR1) ₄ (wherein R1 represents an alkyl group having 1 to 4 carbon atoms), for example, tetramethoxysilane, tetraethoxysilane, and the like. R2 _n Si (OR3) _4n (wherein R2 is a hydrocarbon group having 1 to 6 carbon atoms, R3 is an alkyl group having 1 to 4 carbon atoms, and n is an integer of 1 to 3). Alkoxysilane compounds such as methyltolylmethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, hexamethyldisilazane, hexyltrimethoxysilane and the like are used.

  Further, as the compound 5 having dielectric properties, for example, stearic acid acrylate, reactive silicone oil, dimethyl silicone oil, methylphenyl silicone oil, methyl hydrogen silicone oil, reactive silicone oligomer, for example, Matsushita Electric Industrial Co., Ltd. Fressera D made is used.

  Furthermore, as the compound 5 having dielectric properties, an acrylic monomer having a perfluoroalkyl group such as 2- (perfluoropropyl) ethyl acrylate, 2- (perfluorobutyl) ethyl acrylate, 2- (perfluoropentyl) ethyl acrylate, 2- (perfluorohexyl) ethyl acrylate, 2- (perfluoroheptyl) ethyl acrylate, 2- (perfluorooctyl) ethyl acrylate, 2- (perfluoro Noryl) ethyl acrylate, 2- (perfluorodecyl) ethyl acrylate, 3-perfluorohexyl-2-hydroxypropyl acrylate, perfluorooctylethyl methacrylate, 3-perfluorooctyl-2-hydroxypropyl Acrylate and, 3-perfluorodecyl-2-hydroxypropyl acrylate are used.

  Furthermore, as the compound 5 having dielectric properties, other fluorine compounds such as 2-perfluorooctylethanol, 2-perfluorodecylethanol, 2-perfluoroalkylethanol, perfluoro ( Propyl vinyl ether), perfluoroalkyl iodide, perfluorooctylethylene, 2-perfluorooctylethylphosphonic acid, and the like are used.

Furthermore, as the compound 5 having dielectric properties, a silane coupling agent having a perfluoroalkyl group, such as CF ₃ (CH ₂ ) ₂ Si (OCH ₃ ) ₃ or CF ₃ (CF ₂ ), as a fluorine-based compound. ₅ (CH ₂ ) ₂ Si (OCH ₃ ) ₃ , CF ₃ (CF ₂ ) ₇ (CH ₂ ) ₂ Si (OCH ₃ ) ₃ , CF ₃ (CF ₂ ) ₁₁ (CH ₂ ) ₂ Si (OCH ₃ ) ) ₃ , CF ₃ (CF ₂ ) ₁₅ (CH ₂ ) ₂ Si (OCH ₃ ) ₃ , CF ₃ (CF ₂ ) ₇ (CH ₂ ) ₂ Si (OC ₂ H ₅ ) ₃ , CF ₃ (CH ₂ ) ₂ SiCH ₃ (OCH ₃ ) ₂ , CF ₃ (CF ₂ ) ₂ (CH ₂ ) ₂ SiCH ₃ (OCH ₃ ) ₂ , CF ₃ (CF ₂ ) ₅ (CH ₂ ) ₂ SiCH ₃ (OCH ₃ ) ₂ and, CF _{(CF 2) 7 (CH 2} ) 2 SiCH 3 (OCH 3) 2 _{and, CF 3 (CF 2) 7} (CH 2) 2 SiCH 3 (OC 2 H 5) 2 _{and, CF 3 (CF 2) 7} ( CH ₂ ) ₂ Si (OCH ₃ ) ₃ , CF ₃ (CF ₂ ) ₇ (CH ₂ ) ₂ Si (OC ₂ H ₅ ) ₃ , CH ₃ (CF ₂ ) ₉ (CH ₂ ) ₈ Si (OC ₂ ) H ₅ ) ₃ , CF ₃ (CF ₂ ) ₇ CONH (CH ₂ ) ₃ Si (OCH ₃ ) ₃ , CF ₃ (CF ₂ ) ₇ CONH (CH ₂ ) ₂ SiCH ₃ (OCH ₃ ) ₂ , oligomers having a fluoroalkyl group and silanol groups, for example, KP-801M (Shin-Etsu Chemical Co., Ltd.) and, X-24-7890 (Shin-Etsu Chemical Co., Ltd.) and, Pafuruorobute two vinyl ether and its Such as polymer is used.

  Further, as the compound 5 having dielectric properties, unsaturated polyester, unsaturated acrylic, epoxy acrylate, urethane acrylate, polyester acrylate, polyether acrylate, polybutadiene acrylate, silicone acrylate, maleimide, polyene, etc. / Oligomers such as polythiols, prepolymers, and other alkoxy oligomers are also used. The compound 5 having dielectric properties may be used alone or in combination of two or more.

  The dielectric compound 5 in the thin film 20 composed of the dielectric inorganic fine particles 2 may be added so as to have a content of 0.1% by mass or more with respect to the inorganic fine particles 2 coated with the silane monomer. Particularly, 1% by mass or more is preferable. As the amount of the compound 5 having dielectric properties is increased, the surface potential and the amount of coulomb increase due to electron injection by corona discharge and frictional charging by fibers, films, etc. Can be collected, and the pressure loss, which is a characteristic of the filter, can be further reduced.

  However, vinyl monomers having unsaturated bonds, silane monomers having unsaturated bonds and reactive functional groups, acrylic monomers having perfluoroalkyl groups, silane coupling agents having perfluoroalkyl groups, Dielectric properties such as unsaturated polyester, unsaturated acrylic, epoxy acrylate, urethane acrylate, polyester acrylate, polyether acrylate, polybutadiene acrylate, silicone acrylate, maleimide, oligomers such as polyene / polythiol, etc. When the content of the compound 5 exceeds 40% by mass with respect to the content of the inorganic fine particles 2 coated with the silane monomer, the ratio of covering the surface of the inorganic fine particles 2 is increased, so that dust separation performance is reduced. 40% by mass or less is preferred In particular, 20% by mass or less is preferable.

  If the dust suspension of the attached particulate floating substance decreases, it becomes difficult to remove the particulate floating substance attached to the filter surface, so the particulate floating substance accumulates on the filter surface over time. This leads to a decrease in the collection efficiency and an increase in pressure loss.

  As described above, in the chargeable filter member 200 having excellent dust separation properties according to the second embodiment of the present invention, when charged by electron injection by corona discharge or friction of fibers, films, etc., dielectric inorganic fine particles Since the dielectric compound 5 containing at least one of a monomer, an oligomer, and a polymer is dispersed and compounded in the thin film 20 containing, the surface potential and the coulomb amount are effectively increased. It is possible to efficiently collect micron-order particulate floating substances and provide a filter member with low pressure loss.

(Third embodiment)
Next, the chargeable filter member 300 having excellent dust separation properties according to the third embodiment of the present invention will be described in detail with reference to FIG.

  FIG. 3 is an enlarged view of a part of a cross section of the chargeable filter member 300 having excellent dust separation properties according to the third embodiment of the present invention. The filter member 300 of the present embodiment has at least one of a monomer, an oligomer, and a polymer on the surface of the thin film 30 containing dielectric inorganic fine particles formed of the dielectric inorganic fine particles 2 coated with the silane monomer 3. It differs from the filter member 100 of the first embodiment of the present invention in that the coating 6 of the compound having dielectric properties is coated.

  Hereinafter, the manufacturing method and the configuration of the members, which are different from the filter member 100 according to the first embodiment of the present invention, will be described. Further, with respect to the base material, the fine particle material, and the manufacturing method, the description of the points in common with the filter member 100 of the first embodiment of the present invention will be omitted.

  The required properties of the dielectric compound coating 6 include high water resistance and low moisture permeation, electron injection by corona discharge, and friction between two or more different fibers. For example, it is easily charged by being polarized by frictional charging. In particular, when the humidity is high in the use environment, it is predicted that the chargeability will decrease with time. Therefore, the effect of the coating 6 of the compound having dielectric properties is intended to be compatible with various environments other than improving the charging property.

  Specifically, the coating film 6 of a compound having dielectric properties includes, as a fluorine-based compound, an acrylic monomer having a perfluoroalkyl group, such as 2- (perfluoropropyl) ethyl acrylate or 2- (perfluorobutyl). Ethyl acrylate, 2- (perfluoropentyl) ethyl acrylate, 2- (perfluorohexyl) ethyl acrylate, 2- (perfluoroheptyl) ethyl acrylate, 2- (perfluorooctyl) ethyl acrylate, 2- (Perfluoronolyl) ethyl acrylate, 2- (perfluorodecyl) ethyl acrylate, 3-perfluorohexyl-2-hydroxypropyl acrylate, perfluorooctylethyl methacrylate, 3-perfluorooctyl-2-hydroxyl And pills acrylate, 3-perfluorodecyl-2-hydroxypropyl acrylate are used.

  Further, as the coating 6 of the compound having dielectric properties, other fluorine compounds such as 2-perfluorooctylethanol, 2-perfluorodecylethanol, 2-perfluoroalkylethanol, Fluoro (propyl vinyl ether), perfluoroalkyl iodide, perfluorooctylethylene, 2-perfluorooctylethylphosphonic acid, and the like are used.

Furthermore, as the coating 6 of the compound having dielectric properties, a silane coupling agent having a perfluoroalkyl group, such as CF ₃ (CH ₂ ) ₂ Si (OCH ₃ ) ₃ , CF ₃ (CF ₂ ) ₅ (CH ₂ ) ₂ Si (OCH ₃ ) ₃ , CF ₃ (CF ₂ ) ₇ (CH ₂ ) ₂ Si (OCH ₃ ) ₃ , CF ₃ (CF ₂ ) ₁₁ (CH ₂ ) ₂ Si ( OCH _{3) 3 and, CF 3 (CF 2) 15} (CH 2) 2 Si (OCH 3) 3 _{and, CF 3 (CF 2) 7} (CH 2) 2 Si (OC 2 H 5) 3 and, CF ₃ (CH ₂ ) ₂ SiCH ₃ (OCH ₃ ) ₂ , CF ₃ (CF ₂ ) ₂ (CH ₂ ) ₂ SiCH ₃ (OCH ₃ ) --- ₂ , CF ₃ (CF ₂ ) ₅ (CH ₂ ) ₂ SiCH _{3 (OCH 3) 2 , CF 3 (CF 2) 7} (CH 2) 2 SiCH 3 (OCH 3) 2 _{and, CF 3 (CF 2) 7} (CH 2) 2 SiCH 3 (OC 2 H 5) 2 _and, CF 3 (CF ₂ ) ₇ (CH ₂ ) ₂ Si (OCH ₃ ) ₃ , CF ₃ (CF ₂ ) ₇ (CH ₂ ) ₂ Si (OC ₂ H ₅ ) ₃ , CH ₃ (CF ₂ ) ₉ (CH ₂ ) ₈ Si (OC ₂ H ₅ ) ₃ , CF ₃ (CF ₂ ) ₇ CONH (CH ₂ ) ₃ Si (OCH ₃ ) ₃ , CF ₃ (CF ₂ ) ₇ CONH (CH ₂ ) ₂ SiCH ₃ (OCH ₃ ) ₂ and, oligomers having a perfluoroalkyl group and a silanol group, for example, KP-801M (Shin-Etsu Chemical Co., Ltd.) and, X-24-7890 (Shin-Etsu Chemical Co., Ltd.) and, Pafuruorobute two vinyl ether The polymer and, PTFE, ETFE, PVDF, or the like is used.

  Further, as the coating 6 of the compound having dielectric properties, a reactive silicone oligomer, for example, Fresella D manufactured by Matsushita Electric Industrial Co., Ltd. is used.

  Further, as the coating 6 of a compound having dielectric properties, oligomers and prepolymers such as silicone acrylate, maleimide, polyene / polythiol, polyamideimide, polyimide, polymonochloroparaxylylene, paraxylylene, parylene HT (Nippon Parylene) In addition, alkoxy oligomers are also used. The coating 6 of the compound having dielectric properties may be used alone, or two or more types may be laminated and used.

  Further, in the chargeable filter member 300 excellent in dust separation of the present embodiment, in the thin film 30 containing inorganic fine particles of dielectric, as in the filter member 200 of the second embodiment of the present invention described above, A dielectric compound 5 containing at least one of a monomer, an oligomer, and a polymer may be included.

  The coating film 6 of a compound having dielectric properties in the chargeable filter member 300 excellent in dust separation of the present embodiment is formed on the surface of the thin film 30 made of dielectric inorganic fine particles, and the thickness of the coating film There is no particular limitation as long as the hole is not generated and the surface of the thin film 30 is maintained with a minute uneven shape.

  A specific method for forming the coating film 6 of a compound having dielectric properties is a generally used spin coating method, dip coating method, spray coating method, cast coating method, bar coating method, or micro gravure coating method. Alternatively, a gravure coating method, vacuum deposition, CVD method, or the like may be used, as long as the pinholes are not generated and the minute uneven shape on the surface of the thin film 30 is maintained as described above. There is no particular limitation.

  As described above, according to the chargeable filter member 300 having excellent dust separation characteristics according to the third embodiment of the present invention, at least a monomer, an oligomer, or a polymer is formed on the surface of the thin film 30 made of dielectric inorganic fine particles. Since the coating 6 of a dielectric compound containing any one is coated, the surface potential and coulomb amount can be efficiently charged by electron injection by corona discharge or rubbing two or more different fibers. In addition to improving the chargeability, even when used as a filter in a high humidity environment, the chargeability is less likely to deteriorate with time, and it is possible to maintain chargeability and dust separation for a long period of time. It is possible to provide a filter member that is suitable for an air conditioner, an air purifier, a building air conditioner, a clean room air conditioner, and the like and that has a low pressure loss and a high collection efficiency.

  Further, the unsaturated bond or reactive silane monomer 3 having a reactive unsaturated group or reactive functional group is chemically bonded to the surface of the substrate 1 by the dehydration condensation reaction. The functional inorganic group 2 is introduced and reacted with the unsaturated bonds or reactive functional groups introduced on the surface of the inorganic fine particles 2 or with the fiber surface of the substrate 1 to immobilize the dielectric inorganic fine particles 2. As a result, the filter member of the present embodiment is a thin film made of dielectric inorganic fine particles having excellent durability, in which the inorganic fine particles 2 coated with the silane monomer 3 and the inorganic fine particles 2 and the substrate 1 are strongly bonded. Therefore, it is easy to be charged by corona discharge or friction by a fiber or a film, and the effect can be maintained for a long time.

(Fourth embodiment)
Next, the chargeable filter member 400 having excellent dust separation properties according to the fourth embodiment of the present invention will be described in detail with reference to FIG.

  FIG. 4 is an example of a schematic diagram enlarging a part of a cross section of the chargeable filter member 400 having excellent dust separation characteristics according to the fourth embodiment of the present invention. The filter member 400 of the present embodiment includes only a single inorganic fine particle 2 or a plurality of inorganic fine particles 2 in a thin film 40 including dielectric inorganic fine particles 2 coated with a silane monomer 3, and each of them is scattered. In the first embodiment of the present invention, the gaps 40a and 40b reaching the surface of the base body 1 are formed by being scattered in the shape of islands, and a part of the surface of the base material 1 is exposed. It is different from the filter member 100 of the form.

  In FIG. 4, the filter member 100 according to the first embodiment of the present invention is taken as an example, and the inorganic fine particles 2 in the thin film 40 are present in an island shape and the voids 40 a and 40 b are formed. In the filter member 200 according to the second embodiment of the present invention and the filter member 300 according to the third embodiment, the inorganic fine particles in the thin film are present in the form of islands and the voids are formed. The fourth embodiment can be considered.

  Therefore, regarding the base of the filter member 400 of the fourth embodiment of the present invention, the material of the fine particles, the constituent elements of the member and the manufacturing method, it is the same as the filter member of the first to third embodiments of the present invention, As for the obtained characteristics, similar to the first to third embodiments, the characteristics suitable as a member for a chargeable filter excellent in dust separation are shown. In particular, when an electretized material is used as the base material, since a part of the surface of the base material 1 is exposed, it is in an island shape containing inorganic fine particles while maintaining the characteristics of the base material as an electret. It is possible to impart excellent dust separation properties by the existing thin film.

  As shown in the fourth embodiment of the present invention, as a manufacturing method in which the inorganic fine particles 2 are arranged so as to be scattered in a single or a plurality of islands, for example, compared with the case of forming a normal thin film, inorganic in the solution There is a method of diluting the concentration of the fine particles 2 to about 1/10 to 1/100. Specifically, by applying and drying a dilute solution of about 0.5 mass% to 0.05 mass% as the inorganic fine particles 2 in the solution, the inorganic fine particles 2 are scattered in islands, and a part of the surface of the substrate is exposed. It can be set as the chargeable filter member excellent in dust separation.

  Next, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to only these examples.

  The fine particle immobilization bodies of Examples 1 to 9 and Comparative Example 3 were manufactured by electron beam graft polymerization using an electro curtain type electron beam irradiation apparatus, CB250 / 15 / 180L, manufactured by Iwasaki Electric Co., Ltd. did.

Example 1
Commercially available zirconium oxide particles having a dielectric (Nippon Denko Co., Ltd., PCS) after the dispersion 10.0 wt% in methanol, were ground and dispersed to an average particle diameter of 17 n m by a bead mill. To the resulting dispersion solution, 5.0% by mass of 3-methacryloxypropyltrimethoxysilane (KBM-503, manufactured by Shin-Etsu Chemical Co., Ltd.) having an unsaturated bond or a reactive functional group as a silane monomer was added. Then, this pulverized dispersion solution is transferred to a flask equipped with a cooling tube, and the flask is heated and treated under reflux for 4 hours to chemically bond the silane monomer to the surface of the zirconium oxide fine particles by dehydration condensation to form a coating. did. In addition, the average particle diameter here means a volume average particle diameter.

  The pulverized dispersion was applied to 80 mesh made of polyester and dried at 110 ° C. for 1 minute. Next, a filter member in which zirconium oxide fine particles are bonded to the surface of the polyester mesh by graft polymerization of a silane monomer by irradiating an 80-nm polyester mesh coated with the zirconium oxide fine particle dispersion with an electron beam of 5 Mrad at an acceleration voltage of 200 kV. Got.

(Example 2)
In Example 1, the content of inorganic fine particles in which an oligomer having a perfluoroalkyl group and a silanol group (KP-801M, manufactured by Shin-Etsu Chemical Co., Ltd.) is coated with a silane monomer as a dielectric compound in the pulverized dispersion solution. Except for adding (1) 1% by mass, (2) 5% by mass, (3) 10% by mass, (4) 20% by mass, and (5) 40% by mass. Similar to Example 1.

(Example 3)
In Example 1, (1) 1% by mass with respect to the content of inorganic fine particles coated with modified silane (Granol 100 manufactured by Kyoeisha Chemical Co., Ltd.) with a silane monomer as a dielectric compound in the pulverized dispersion solution, (2) It is the same as Example 1 except for adding so that it may become content of 5 mass% and (3) 10 mass%.

Example 4
In Example 1, paraxylylene (manufactured by Japan Parylene Co., Ltd.) was further formed on the obtained inorganic fine particle thin film by chemical vapor deposition (hereinafter abbreviated as CVD).

(Example 5)
In Example 1, on the inorganic fine particles thin film obtained was applied to Pafuruorobute two vinyl ether polymer (manufactured by Asahi Glass Co., Ltd. CYTOP).

(Example 6)
In Example 2 (2), Pafuruorobute on the inorganic particle thin film obtained two vinyl ether polymer (manufactured by Asahi Glass Co., Ltd. CYTOP) was applied.

(Example 7)
The substrate was the same as Example 5 except that the electret nonwoven fabric (GS-85 manufactured by Sumitomo 3M Limited) and the drying temperature were changed to 70 ° C.

(Example 8)
The substrate was the same as Example 1 except that the substrate was electret nonwoven fabric (GS-85 manufactured by Sumitomo 3M Limited) and the drying temperature was changed to 70 ° C.

Example 9
Example 1 was the same as Example 8 except that the pulverized dispersion was diluted 30-fold with methanol and applied so that the thin film containing inorganic fine particles was present in the form of islands on the substrate surface.

(Comparative Example 1)
The polyester 80 mesh was not subjected to any treatment and was evaluated as it was.

(Comparative Example 2)
A conductive tin oxide dispersion (Catalyst Chemical Industries, ELCOM P-30) was applied to 80 mesh made of polyester to obtain a filter member.

(Comparative Example 3)
In Example 1, the content of inorganic fine particles in which an oligomer having a perfluoroalkyl group and a silanol group (KP-801M, manufactured by Shin-Etsu Chemical Co., Ltd.) is coated with a silane monomer as a dielectric compound in the pulverized dispersion solution. When a large amount is added so that the content becomes 200% by mass, the structure as a filter member is similar to that of Example 2, but the inorganic fine particles of the dielectric are fixed by the conventional binder method The composition is assumed to be a film formed on the surface.

(Comparative Example 4)
The electret nonwoven fabric (GS-85 manufactured by Sumitomo 3M Limited) was not subjected to any treatment, and the properties were evaluated as they were.

  Table 1 and Table 2 summarize the above conditions.

(Characteristic evaluation)
To collect dust, each sample is cut to a size of 10 x 10 cm and charged, and then the test sample is brought close to a bat containing carbon black compliant with JISZ 8901, and the carbon black is collected by the Coulomb force generated by charging. Went. The dust collection property of carbon black was evaluated by measuring the mass of the test sample before and after carbon black deposition.

  In addition, dust separation is performed by tapping the test sample after collecting dust, shaking off the carbon black adhering to the sample surface, measuring the mass of the test sample, and removing the remaining carbon black adhering to the sample surface. It was evaluated as separability.

  Furthermore, as another evaluation method of dust separation property, the test sample after dust collection was evaluated by removing electricity. Using a static electricity removal device (KD-410 type) manufactured by Kasuga Electric Co., Ltd., the test sample surface was neutralized, the test sample mass was measured, and the carbon black that remained on the sample surface was removed. It was assumed to be separated.

  In addition, charging was applied to the test sample by applying a voltage to the test sample (10 × 10 cm) using a small high-voltage power supply (GT-20 minus type) manufactured by Green Techno Co., Ltd. The test environment was evaluated at 24 ° C. and 70% RH.

  The surface voltage was measured by using an electrostatic potential measuring device (KSD-0103 type) manufactured by Kasuga Electric Co., Ltd., with the sensor approaching the test sample (10 × 10 cm).

  The above test results are shown in Table 3.

  From the results of Table 3, in Examples 1 to 6 using a polyester mesh as a substrate and Examples 7 to 9 using an electret nonwoven fabric as a substrate, the dust collecting property depends on the voltage level before dust collection due to the difference in the substrate. However, it can be seen that the carbon black sucked and collected by the Coulomb force due to charging can be shaken off from the sample surface by light vibration or static elimination in all the examples. Furthermore, in Examples 2, 3, and 6, by compounding a compound having dielectric properties, the charged voltage can be increased, and the dust collecting property can be improved while maintaining excellent dust separation properties.

  On the other hand, although Comparative Example 1 is charged, if it adheres to the sample surface, carbon black remains on the surface even if the charge is removed, and the filter becomes clogged and the pressure loss becomes high.

  In Comparative Example 2, a conductive thin film is formed on the mesh surface so that even if a charge is applied, the conductive film is conductive and therefore is not charged. As a result, no dust collecting property is observed.

  In Comparative Example 3, assuming a film in which fine particles are fixed by a conventional binder method, 200% by mass of a dielectric compound is used with respect to dielectric zirconium oxide fine particles coated with a silane monomer. A thin film was formed on the mesh surface. In this case, although the dust collection effect due to electrification is manifested, no dust separation is observed.

  In Comparative Example 4 in which a commercially available polypropylene electret nonwoven fabric is used as it is, the pre-dust collection voltage and the dust collection property due to electrification show the same characteristics as Examples 7, 8, and 9 subjected to the treatment of the present invention. However, it is clear that the dust-removing property is remarkably inferior.

(Durability evaluation)
As an index indicating the durability of the dust collection performance due to charging, the state in which the initial charged voltage changes with time was measured. In Examples 2- (2) and 6 using a polyester mesh as a substrate, charging was applied, and in Examples 8 and 9 and Comparative Example 4 using an electret as a substrate, no charging was applied. The time-dependent change in voltage was measured in a high humidity environment of 24 ° C. and 80% RH, and the results are shown in Table 4.

  From the results of Table 4, although the initial charged voltage is high in Example 2- (2) using a polyester mesh as the substrate, the charged voltage decreases in a relatively short time in a high humidity environment such as this test. On the other hand, in Example 6 in which the surface of the inorganic fine particle thin film obtained in Example 2- (2) was covered with a dielectric compound, the charged voltage was reduced over time even in a high humidity environment. Can be suppressed.

  In addition, Example 8 using an electret as the substrate also shows a decrease in the charged voltage in a relatively short time, as in Example 2- (2). On the other hand, in the comparative example 4 which does not perform a process, the property of the electret which a base | substrate has originally is maintained, and even if it is a high-humidity environment, the voltage drop with time is little.

  In Example 9 in which the inorganic fine particles 2 are arranged in an island shape, the electret's original properties are maintained as an effect that a part of the surface of the substrate is exposed, so that the voltage over time is maintained even in a high humidity environment. The decrease in the resistance is small, the dustlet removability is excellent, and a suitable characteristic as a durable electret filter is exhibited.

The schematic diagram of the member for chargeable filters excellent in the dust separation property of 1st Embodiment of this invention. The schematic diagram of the member for chargeable filters excellent in the dust separation property of 2nd Embodiment of this invention. The schematic diagram of the member for chargeable filters excellent in the dust separation property of 3rd Embodiment of this invention. The schematic diagram of the member for chargeable filters excellent in the dust separation property of 4th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100: Member for chargeable filter excellent in dust separation property of 1st Embodiment of this invention 1: Base | substrate 2: Inorganic fine particle 3: Silane monomer 4: Chemical bond 10: Thin film containing the inorganic fine particle of dielectric material 200: This invention 5: Chargeable filter member excellent in dust separation of the second embodiment 5: Compound having dielectric properties 20: Thin film containing inorganic fine particles of dielectric material 300: Excellent dust separation of the third embodiment of the present invention Charge filter member 6: Coating film containing dielectric compound 30: Dielectric thin film containing inorganic fine particles 400: Charge filter member excellent in dust-removability according to the fourth embodiment of the present invention 40: Dielectric Thin films containing various inorganic fine particles

Claims (4)

Ri Do a resin fiber, and electret possible substrates,
A thin film provided on the surface of the substrate, including dielectric inorganic fine particles coated with a silane monomer having an unsaturated bond or a reactive functional group;
Have
The inorganic fine particles in the thin film form the thin film by chemically bonding the unsaturated bond or reactive functional group of each other silane monomer, and the unsaturated bond of the silane monomer of the inorganic fine particle in the thin film or When the reactive functional group and the surface portion of the substrate are chemically bonded, the substrate and the thin film are fixed,
The thin film is
The inorganic fine particles have a void formed by being scattered in a single or plural island shape, and a part of the surface of the substrate is exposed through the void.
A member for a chargeable filter excellent in dust separation, comprising at least one compound having dielectric properties selected from the group consisting of a monomer, an oligomer and a polymer. The thin film is
2. The member for a chargeable filter excellent in dust separation characteristics according to claim 1, wherein a film containing the compound having dielectric properties is formed on a surface. The chemical bond is
Dust separation excellent in chargeability filter member according to claim 1 or 2, characterized in that the graft polymerization. The graft polymerization is
The chargeable filter member according to claim 3 , wherein the chargeable filter member is excellent in dust separation.

Images